Pressure control valve



July 1, 1952 H. CRUZAN 2,601,745

PRESSURE CONTROL VALVE Filed Nov. 22, 1944 2 SI-IEETS -SE-EET l t HAROLD GRUZAN or (Ittorneg 1, 1952 H, CRUZAN 2,601,745

PRESSURE CONTROL VALVE Filed Nov. 22. 1944 2SHEETS-SHEET 2 3nuentor HAROLD CRUZAN (Ittorneg Patented July 1, 1952 UNITED STATES PATENT OFFICE PRESSURE CONTROL VALVE Harold Cruzan, Beverly Hills, Calif., assignor to The Garrett Corporation, Airesearch Manufacturing Company division, Los Angeles, Calif., a corporation of California Application November 22, 1944, Serial No. 564,582

3 Claims. 1

This invention relates to fluid pressure control valves and has as its object to provide a valve adapted to control the pressure in a moving stream of fluid Without being affected by the fluid movement.

More specifically, the invention aims to provide a valve in which the flow of a fluid .is controlled by two balanced valve elements, one closing with and the other closing against the flow of the fluid, so that the effect of the fluid pressure and flow on one valve is balanced by an opposite effect on the other valve.

Another object of the invention is to provide, in a balanced valve, a simple arrangement whereby both valve elements are adapted to be simultaneously moved toward open or closed positions by a pressure responsive actuator.

A further object is to provide, in such a valve, an arrangement ensuring the full seatingwof both valve elements.

Another object is to provide a pressure control valve adapted to be employed in a fluid pressure system in which a fluid is pumped from a wherein the pressure must be controlled with accuracy, and it is also adaptable to the control of the pressurization of fuel tanks for aircraft, etc.

In addition to the foregoing objects, the inven tion aims to provide a valve which is of relatively simple construction, and easily serviced.

Further objects and advantages of the invention will appear in the following part of the specification.

Referring to the drawin which are for i1lus-. 'trative purposes only:

Fig. 1 is a schematic diagram of an aircraft cabin pressurization system incorporating a mum ber of valves embodying the invention;

Fig. 2 is a plan view of one of the valves;

Fig. 3 is a vertical longitudinal sectional view of the valve; and

Fig. 4 isa vertical longitudinal sectional view of a valve embodying a modified forinof-the in vention.

The system shown in Fig. 1, for the purpose of illustrating an arrangement in which the valve of my invention is particularly useful, includes a pressure source (such as a supercharger) 6 adapted to supply air under pressure through a duct 1 to the cabin enclosure 8 of a pressurized cabin aircraft. The "air from the duct 1 passes to the enclosure 8 througha flow control valve 9. The outflow from the cabin is controlled by a pressure regulator In, which is vented to the atmosphere. A maximum pressure in the cabin enclosure 8 may be regulated by a pressure relief valve A vacuum relief valve l2 functions to equalize the pressure in the cabin enclosure 8 with ambient atmospheric pressure when the latter exceeds the cabin pressure.

The pressure source 6, in addition to its main function of supplying air to the cabin enclosure 8 for ventilating and maintaining the desired pressure therein, may also apply pressure to the fuel in tanks I3 and l3a, through branch air lines I4 and Ma. A portion of the air pumped by the pressure source 6 mayalso be diverted, through an air line I5, 'to an instrument or number of instruments l6 within the cabin enclosure 3, for operating the same.

The pressure applied to the fuel tanks l3 and 13a and to the instruments 5 is regulated by pressure controlled valves [1, Ha, and I8, all of which incorporate the present invention.

Referring now to Figs. 2 and 3, my pressure regulating valve embodies three separable housing sections 2|, 22, and 23, the sections 2| and 22 being secured together by bolts 24, with the gasket 26 interposed .therebetween, and the sections 22 and 23 being secured together by bolts 2! with a flexible diaphragm 28, of rubber or equivalent material, interposed therebetween and serving as a gasket as Well as a pressure sensitive element for operating the valve. The housing section 2| is formed with a fluid inlet 29. The intermediate housing section 22 is formed with a fluid outlet 39 and with a wall 3| which forms a barrier be tween the mating valve housing portions 33 and 34 respectively of the sections 2| and 22. The intermediate section .22 includes a radially extendin flange 35 having around its periphery a rim portion 36 cooperating with the rim of the lateral wall 31 of the section 23 to clamp the diaphragm 28.

The sections 2| and 22 and the diaphragm 2B cooperate to define a fluid flow passage which is traversed by the wall 3| and divided thereby into two parallel passages comprising the valveports 38 and 39 which are formed in the Wall 3|.

Spherical valve elements 40 and 4| cooperate with valve seats formed at the edges of the ports 38 and 39 on opposite sides of the wall 3|, the valve element 40 closing against the flow of the fluid and the valve element 4| closing with the flow of the fluid.

Simultaneous opening and closing movements are transmitted to the valve elements 48 and 4| by a rocker arm 42 fulcrumed on a pin 43, the ends of which are mounted in the wall portion 34 of the housing section 22. The valve 4| is threaded onto the end of a link 44 which projects through the port 39, is pivoted to the rocker arm 42 at 46, extends beyond the rocker arm and is attached to the center of the diaphragm 28. A pair of washers 47 and 48 engage the opposite sides of the central region of the diaphragm and the link 44 is provided with a reduced threaded end 49 which extends through the washers 41 and 48 and has threaded thereon a nut Which secures the several parts in assembly.

The valve element 49 is yieldingly engaged by a frusto-conical coil spring 52 which is secured to the end of an adjusting screw 53 threaded through the other end of the rocker arm 42 and secured by a lock nut 54.

The intermediate housing section 34 cooperates with the diaphragm 28 to define a pressure chamber 56 in which the pressure of the fluid flowing through the valves is applied to the upper side of the diaphragm 28. Opposing this pressure is the pressure of the spring 57 against the other side of the diaphragm and the pressure from a vent l8, the spring 5! being engaged between the washer 48 (which has a peripheral flange 58 for piloting the spring) and an adjustable plate 59 (similarly flanged) having a cylindrical shank 6| piloted in a bore 62 in an adjusting screw 63 which'is threaded in the bottom wall 64 of the housing section 23. A look nut 65 secures the adjusting screw 63 in any position to which it is adjusted. By varying the position of the adjusting screw 53, the pressure exerted against the diaphragm 28 by the spring 5'! may be varied, and the pressure at which the valves 40 and 4| will close is correspondingly varied.

To avoid injury to the valve mechanism which might result from pressure surges embodying pressures considerably in excess of the valve closing pressures, I provide a pressure relief passage.

61, formed partially in the housing section 22 and partially in the housing section 23, the upper end of the passage 51 communicating through a port 68 with the pressure chamber 55 and the lower end of the passage 51 communicating through a port 69 with the spring housing chamber ill defined between the diaphragm and the section 23. An enlarged extension 7| of the passage Bl forms, at the junction therewith, a valve seat against which is normally seated a ball valve element 72. A pressure higher than the pressure at which the valve elements 4@ and 4| are adapted to close, is yieldingly exerted against the valve element 12 b a spring 73, the compression of which may be varied by an adjusting screw 14 threaded into the lower end of the passage extension 7| and secured by a lock nut 15. A relief valve opening pressure is set at a slightly higher level than the closing pressure for the valves 46 and 4|, in order that the relief valve may normally remain closed, but will open to relieve excessive pressures above the normal valve closing pressure. The spring housing chamber H1 is vented through a vent 16 in the bottom housing wall 64.

4 The spring housing chamber Ill may be vented either to the atmosphere or to the cabin enclosure, depending upon the pressure to be held by the valve. The valve I! which controls the pressure in the tank I3 is vented to atmosphere.

Where it is desired to vent the valve to the cabin, and to have the valve located outside of the cabin enclosure, a vent tube 11 communicating with the spring housing chamber 10 may be employed. As an example of such an arrangement, the valve I8 is shown in Fig. l as being located outside the cabin and connected to the cabin by such a vent tube.

In the operation of the valve, as long as the pressure in the chamber 56 is below the critical valve closing pressure, the spring 51 will maintain the diaphragm in a position in which the valve element 4| is held away from contact with its valve seat and the valve element 40 is permitted to be held away from contact with its seat by the action. of the fluid flowing through the port 38. The pressure of the fluid flow against the valves 49 and 4| is substantially balanced, through the rocker arm 42, the fulcrum 43 being located midway between the axes of the valves 40 and 4|. When the pressure in the chamber 56 is raised to the critical valve closing point, the diaphragm 28, acting under such pressure and overcoming the pressure of the spring 51, will move to a position wherein the valve 4| will be drawn to closed position and the valve element 40 will be yieldingly pushed to its closed position.

The pressure exerted by the spring 51 is equal to the differential between the valve closing pressure (for example, the pressure to be maintained in the fuel tanks l3 and I3a) and the vent pressure.

It may be important in many installations to provide for holding the pressure in the chamber closed by the valve, and for this purpose I provide, as shown in Fig. 4, a check valve in the form of a disc 18 adaped to engage a valve seat 19 in the inlet 29 and to close under the back pressure from such chamber in the event of failure of the pressure source. The closing movement is assured and assisted by a light spring 80.

With the exception of the above described feature, the valve shown in Fig. 4 is the same in construction as the valve shown in Figs. 2 and 3, and similar reference numerals have been employed to indicate those parts which are shown, the majority of the valve being shown in elevation to avoid duplication of the identical parts.

I claim as my invention:

1. A fluid pressure control valve, comprising: means forming a fluid flow passage having a barrier thereacross provided with a pair of ports through which the fluid may flow in a divided stream; a rocker arm pivoted intermediate its ends and located in said passage; a pair of valve members for controlling said ports; a link connecting one end of said rocker arm to one of said valves; an adjustable screw on the other end of said rocker arm; a yielding connection between said screw and the other of said valves, said yielding connection being attached at one end to said screw and said link and yielding connection being adapted to transmit closing movement from said rocker arm simultaneously to both of said valves; and an actuator responsive to a predetermined increase in pressure in said passage for transmitting such closing movement to said rocker arm.

2. A fluid pressure control valve, comprising:

means forming a passage having a barrier provided with a pair of ports through which liquid may flow in separated streams; a pair of balanced ball valves for controlling said ports, one of said valves being on one side of said barrier and the other of said valves being on the opposite side of said barrier, closable, one with and the other against the fluid flow for arresting said fluid flow; a rocker arm in said passage pivoted intermediate its ends; a, link pivoted to one end of said rocker arm and having a threaded end which projects through one of said ports, one of said ball valves being threadably mounted on said threaded end; an adjustment screw on the opposite end of said rocker arm; a spring connected to said screw and providing a yielding connection with the other of said ball valves, said yielding connection pressing said other ball valve toward closed position; and means forming an enlarged pressure chamber in communication with said passage, said means including as one Wall thereof a flexible diaphragm sensitive to the pressure in said chamber, said link being attached to said diaphragm.

3. In a fluid pressure control valve, means forming a fluid flow passage having a barrier thereacross provided with a pair of ports through which the fluid may flow in divided streams, a rocker arm pivoted intermediate its ends in said passage, a pair of valve members for controlling said ports, a link connecting one end of said rocker arm to one of said valves, an adjustable 6 screw on the other end of said rocker arm, a yielding connection between said screw and the other valve, said link and yielding connection being adapted to transmit closing movement from said rocker arm simultaneously to both of said valves, and an actuator responsive to a predetermined increase in pressure in said passage for transmitting such closing movement to said rocker arm.

HAROLD CRUZAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 151,580 Eversol June 2, 1874 329,928 Merrill Nov. 10, 1885 548,172 Bastain Oct. 22, 1895 601,878 Matchett Apr. 5, 1898 702,236 McAdams June 10, 1902 1,843,953 McKinney Feb. 9, 1932 2,013,222 Thomas Sept. 3, 1935 2,047,101 Grove July 7, 1936 2,053,931 Work Sept. 8, 1936 2,119,471 Messinger May 31, 1938 2,338,760 Deming Jan. 11, 1944 FOREIGN PATENTS Number Country Date 164,617 Switzerland Dec. 16, 1933 

